Surface plasmons, charge density waves propagating along metal-dielectric interfaces, are applied in bio-molecular detection (see references [1]-[3], incorporated by reference herein in their entirety), sub-wavelength optics (see references [4]-[6], incorporated by reference herein in their entirety), molecular specific surface enhanced Raman spectroscopy (SERS), plasmonic laser devices, and photovoltaic technology (see references [7]-[9], incorporated by reference herein in their entirety). These applications require high extinction strength of plasmonic resonances such that near field effects dominate physical behavior of the plasmonic resonances, hence design considerations for optimal structures aim to control both resonant wavelength and coupling with incident light.
Different geometries have been employed to study plasmonic structures. A horizontal layer approach provides excellent thickness control, but results in fewer plasmonic nanostructures per unit area (see reference [10], incorporated by reference herein in its entirety). Vertical structures provide good coverage, but require complex fabrication and are less amenable to large area substrates (see reference [11], incorporated by reference herein in its entirety).